PDENT800: Posterior Restorations Stainless Steel Crowns (SSC)

Indications of Posterior SSC

decayed teeth

pulpal therapy

hypoplastic / hereditary

high caries risk

special needs

T/F: Posterior SSC are indicated for attachments for space maintainers

TRUE

Contraindications for Posterior SSC

non-restorable teeth

exfoliate soon

occlusal interreferences

esthetics

allergy to SS or nickel

What is the biggest disadvantage to SSC?

Esthetics!

SSC placed in children ages 4 and younger have a success rate approximately ____that of amalgams for each year up to 10 years in service

2x

Failure rate for SSC

1.9-30.3%

Failure rate for amalgam

11.6-88.7%

There is up to ___ failed amalgams for every failed SSC

9

Crowns placed in younger children (<4 years) had a success rate approximately ___ that of Class II Amalgams

2x

Where is the greatest convexity of a posterior molar?

cervical 1/3

T/F: There is an occlusal buccal bulge in the posterior

FALSE

cervical buccal bulge

Which molars have a prominent cervical bulge?

Primary First Molars

Mesial of primary 1st molars have tooth structure that is ____ for Class II restorations

inadequate (pulp horn)

Distal of primary first molars have a ___ preparation and ___ walls

shallow

weak

It is easy to hit ____in primary first molars

pulp

Summary of Clinical Technique

1. Evaluate pre-op occlusion/ marginal ridge height

2. Administer LA

3. Place RD/ Isolation System

4. Crown Preparation

5. Select stie

6. Cementation

Steps for Crown Preparation

1. Occlusal Reduction

2. Excavate Decay

3. Proximal Reduction

4. Buccal and Lingual Reduction

5. Round all line angles

Depth of Occlusal Reduction for SSC

1.0-1.5 mm

Which bur for Occlusal Reduction?

169 football

wheel bur

tapered fissure diamond

Excavate with what bur?

slow speed 6,8 round bur

How much occlusal clearance do you want?

1.0 mm

Which bur to break contacts?

flame-shaped diamond

169L

___ edge finish line for proximal reduction

feather

T/F: Create a margin/ledge for proximal reduction for SSC

FALSE

Break contact ___ and ___

B/L

gingivally

In primary teeth, proximal contacts often extend ___

subgingival

The crown margin seats at the ____ which will be subgingival

CEJ

T/F: Do not pre-wedge so that you increase risk of hitting adjacent tooth

FALSE

Buccal reduction is only where?

occlusal 1/3

What angle is a buccal reduction?

30-45 degrees

T/F: Prep the buccal bulge

FALSE

Do ___ prep the buccal bulge

DO NOT

Rarely will you need to prep the ___ and ___ surfaces

buccal

lingual

Retention for a stainless steal crown comes from ____

bucca bulge

SSC is composed of ___% Nickel, ___% Chromium, and ___% iron

77

15

7

Preform Crown Brand

Unitek

Unitek requires ___ and ____

contouring and trimming

Pre-cut/Pre-contoured crowns

Ion

Ion has ____ trimming and contouring

minimal

A crown should fit ___ mm subginigval

1

A crown that is too ___ is better than ___

long

short

Trimming crown will yield a ________ ______, hence too big

larger circumference

First Molar Gingival Contour Shape

nike swoosh

Second Molar Gingival Contour Shape

Smiley face

Interproximal gingival contour shape

frowny face

Contouring involves bending the ____ to adapt to the tooth

gingival 1/3

Crimping ___ the margin closed

cinches

Contour Pliers

no 114 pliers

T/F: Crimping shortens the crown a lot

FALSE

Crimp which part first?

Mesial --> Distal

BUccal --> LIngual

Crimping Pliers

box crimpers

Use a wrist movement to ___ metal margin inward

Pull

Crown must have __ margin

closed

*****Key: Make sure the ____ ____ is flush with adjacent teeth

occlusal table

What do you use to remove a SSC?

Walls Carver

Discoid

What cements are used?

Ketac

RMGI

__ the crown to margin with cement

Fill

T/F: you can adjust a SSC that is too high

FALSE

How thick is a SSC?

1 mm

What do you do if the SSC is too high?

take off

place a new crown

For adjacent crowns, what is the minimum mm between the gingival margin?

1. 5 mm

Plier to Flatten Interproximal contacts

How Plier

If there is space loss on a mandibular first molar, you can use?

contralateral first molar

Cementation Issues

over/under reduction

large ledge

contact not broken

crown too long

inadequate crimp

incorrect crown size

Cementation Complications

not seated equally

excessive blanching

crown loss

periodontal issues

Excessive Blanching of SSC indicates

crown is too long

crown is overcontoured

T/F: If there is a wear facet, it is best to fix with restorative material?

FALSE

--> better to replace

SSC permanent restoration indication

special needs

SSC Interin Restoration

developmental malformations

trauma

pulp therapy

What size crown do we normally use?

4

Primary First Molar Crown Letter

D

Primary Second Molar Crown Letter

E